Method and apparatus for adjusting subpixel intensity values based upon luminance characteristics of the subpixels for improved viewing angle characteristics of liquid crystal displays

A programmable storage device readable by a digital processing apparatus and tangibly embodying a program of instructions executable by the digital processing apparatus to perform method steps for generating an image for display on a display device having a plurality of subpixels, the method steps comprising:

• providing luminance data, in digital form, which associates intensity values with corresponding luminance values characterizing luminance of said subpixels in at least one viewing angle direction for a range of said intensity values;
• providing a group of subpixel data elements representing color of a portion of said image, wherein each of said subpixel data elements comprises an intensity value;
• modifying said intensity values for said subpixel data elements in said group based upon said luminance data to reduce the number of said subpixels that have a luminance value in a range of mid-tone luminance values between a bright luminance value and a dark luminance value;
• and
• outputting said modified intensity values for said subpixel data elements of said group for display on said display device, wherein the modifying step further comprises the sub-steps of:
• storing, in a first memory, a plurality of entries each providing an association between an intensity value and a corresponding luminance value characterizing luminance of said subpixels in at least one viewing angle direction;
• storing, in a second memory, a plurality of entries each providing an association between a target intensity value and a corresponding set of intensity values that are above and below said target intensity value;
• identifying particular luminance values stored in said first memory that correspond to intensity values of said subpixel data elements of said group;
• generating a first luminance value based upon the particular luminance values stored in said first memory;
• identifying a first target intensity value stored in said first memory corresponding to said first luminance value;
• identifying a particular set of intensity values stored in said second memory that correspond to said first target intensity value;
• and
• modifying intensity values for said subpixel data elements in said group based upon said particular set of intensity values.

An apparatus for generating an image for display on a display device having a plurality of subpixels comprising:

• a first memory wherein luminance data, in digital form, which associates intensity values with corresponding luminance values characterizing luminance of said subpixels in at least one viewing angle direction for a range of intensity values, are stored;
• a second memory wherein a group of subpixel data elements representing color of a portion of said image are stored, wherein said subpixel data elements are logically partitioned into rows and columns and each of said subpixel data elements comprises an intensity value;
• and
• an intensity controller which modifies said intensity values for said subpixel data elements in said group based upon said luminance data to reduce the number of said subpixels that have a luminance value in a range of mid-tone luminance values between a bright luminance value and a dark luminance value, wherein
• said subpixels corresponding to said modified intensity values are arranged in pairs of subpixels, wherein for each pair of subpixels, the luminance of a first subpixel of said pair of subpixels is brighter than the average luminance of said pair of subpixels and the luminance of a second subpixel of said pair of subpixels is darker than the average luminance of said pair of subpixels, and
• a pixel pattern has a periodicity of one of 2 full pixels along said rows and 2 full pixels along said columns, 2 full pixels along said rows and 4 full pixels along said columns, or 4 full pixels along said rows and 2 full pixels along said columns, wherein said pair of subpixels are elements of full pixels which are adjacent to each other in said image.

A computer, comprising:

• a display device which displays an image;
• and
• a processor which provides data to said display device, wherein said data is configured to control said display device in order to display said image, and wherein said data is configured so that said image is displayed as:
• a plurality of subpixels logically partitioned into a first category and a second category, wherein:
• the first category of subpixels are supplied with a data signal of a first polarity,
• the second category of subpixels are supplied with a data signal of a second polarity opposite said first polarity, and
• the subpixels are partitioned to reduce perceived flicker in the displayed image;
• and wherein:
• the subpixels correspond to data elements representing color of at least a portion of said image,
• each of said data elements comprises an intensity value,
• said data elements representing said image are logically partitioned into rows and columns,
• each of said subpixels corresponds to a data element representing a particular color in a group of two or more colors,
• a full pixel comprises subpixels corresponding to the colors of said group,
• said intensity values have been modified to reduce the number of said data elements having a luminance value corresponding to said intensity value in a range of mid-tone luminance values between a bright luminance value and a dark luminance value,
• said subpixels corresponding to said modified intensity values are arranged in pairs of subpixels, wherein for each pair of subpixels, the luminance of a first subpixel of said pair of subpixels is brighter than the average luminance of said pair of subpixels and the luminance of a second subpixel of said pair of subpixels is darker than the average luminance of said pair of subpixels, and
• a pixel pattern has a periodicity of 2 full pixels along said rows and 2 full pixels alone said columns, wherein said pair of subpixels are elements of full pixels which are adjacent to each other in said image and wherein for each full pixel comprising subpixels corresponding to said modified intensity values, said subpixels comprising said full pixel are one of said second subpixels of said pair of subpixels and said first subpixels of said pair of subpixels.

A method for generating an image for display on a display device having a plurality of subpixels, the method comprising the steps of:

• Providing, in digital form, luminance data which associates intensity values with corresponding luminance values characterizing luminance of said subpixels in at least one viewing angle direction for a range of said intensity values;
• providing a group of subpixel data elements representing color of a portion of said image, wherein each of said subpixel data elements comprises an intensity value;
• modifying said intensity values for said subpixel data elements in said group based upon said luminance data to reduce the number of said subpixels that have a luminance value in a range of mid-tone luminance values between a bright luminance value and a dark luminance value;
• and
• outputting said modified intensity values for said subpixel data elements of said group for display on said display device, wherein the modifying step further comprises the sub-steps of:
• storing, in a first memory a plurally of entries each providing an association between an intensity value and a corresponding luminance value characterizing luminance of said subpixels in at least one viewing angle direction;
• storing, in a second memory, a plurality of entries each providing an association between a target intensity value and a corresponding set of intensity values that are above and below said target intensity value;
• identifying particular luminance values stored in said first memory that correspond to intensity values of said subpixel data elements of said group;
• generating a first luminance value based upon the particular luminance values stored in said first memory;
• identifying a first target intensity value stored in said first memory corresponding to said first luminance value;
• identifying a particular set of intensity values stored in said second memory that correspond to said first target intensity value;
• and
• modifying intensity values for said subpixel data elements in said group based upon said particular set of intensity values.

A computer, comprising:

• a display device which displays an image;
• and
• a processor which provides data to said display device, wherein said data is configured to control said display device in order to display said image, and wherein said data is configured so that said image is displayed as:
• a plurality of subpixels logically partitioned into a first category and a second category, wherein:
• the first category of subpixels are supplied with a data signal of a first polarity,
• the second category of subpixels are supplied with a data signal of a second polarity opposite said first polarity, and
• the subpixels are partitioned to reduce perceived flicker in the displayed image;
• and wherein:
• the subpixels correspond to data elements representing color of at least a portion of said image,
• each of said data elements comprises an intensity value,
• said data elements representing said image are logically partitioned into rows and columns,
• each of said subpixels corresponds to a data element representing a particular color in a group of two or more colors,
• a full pixel comprises subpixels corresponding to the colors of said group,
• said intensity values have been modified to reduce the number of said data elements having a luminance value corresponding to said intensity value in a range of mid-tone luminance values between a bright luminance value and a dark luminance value,
• said subpixels corresponding to said modified intensity values are arranged in pairs of subpixels, wherein for each pair of subpixels, the luminance of a first subpixel of said pair of subpixels is brighter than the average luminance of said pair of subpixels and the luminance of a second subpixel of said pair of subpixels is darker than the average luminance of said pair of subpixels, and
• a pixel pattern has a periodicity of one of 2 full pixels along said rows and 4 full pixels along said columns or 4 full pixels along said rows and 2 full pixels along said columns, wherein said pair of subpixels are elements of full pixels which are adjacent to each other in said image.

A computer, comprising:

• a display device which displays an image;
• and
• a processor which provides data to said display device, wherein said data is configured to control said display device in order to display said image, and wherein said data is configured so that said image is displayed as:
• a plurality of subpixels logically partitioned into a first category and a second category, wherein:
• the first category of subpixels are supplied with a data signal of a first polarity,
• the second category of subpixels are supplied with a data signal of a second polarity opposite said first polarity, and
• the subpixels are partitioned to reduce perceived flicker in the displayed image;
• and wherein
• the subpixels correspond to data elements representing color of at least a portion of said image,
• each of said data elements comprises an intensity value,
• said data elements representing said image are logically partitioned into rows and columns,
• each of said subpixels corresponds to a data element representing a particular color in a group of two or more colors,
• a full pixel comprises subpixels corresponding to the colors of said group,
• said intensity values have been modified to reduce the number of said data elements having a luminance value corresponding to said intensity value in a range of mid-tone luminance values between a bright luminance value and a dark luminance value,
• said subpixels corresponding to said modified intensity values are arranged in pairs of subpixels, wherein for each pair of subpixels, the luminance of a first subpixel of said pair of subpixels is brighter than the average luminance of said pair of subpixels and the luminance of a second subpixel of said pair of subpixels is darker than the average luminance of said pair of subpixels, and
• a pixel pattern has a periodicity of 2 full pixels along said rows and 2 subpixels along said columns, and wherein said subpixels are arranged in rows alternating between a first row of adjacent couples comprising said first subpixels of said pair of subpixels, separated by one of said second subpixels of said pair of subpixels and a second row of adjacent couples comprising said second subpixels of said pair of subpixels, separated by one of said first subpixels of said pair of subpixels.